The
Norfolk Broads are an artificial landscape of outstanding natural
beauty, a man made wetland sustained through human intervention of water
pumping mills, dykes and canals. After hundreds of years of indus-
trial use of the natural landscape, the recent decades have seen
increasing emphasis on conservation and a managed retreat back to
nature. The Hunsett Mill project was founded on similar principles,
whereby careless piecemeal development, harmful to the immediate context
and in conflict with local flood ecology was removed and replaced with
an intervention that is contemporary in expression but deeply embedded
in the local context. It is all but self sufficient in energy, water and
waste, with an ac- tively positive effect on local ecology. The design
considered its embodied energy and method of construction as well as its
efficiency during occupa- tion. The environmental aims are directly
embodied in the architectural concept to achieve a building that appears
robust, pure and simple , with a clarity of space and consistency
across scales and materialities.

Project Background

Hunsett
Mill is a remote water pumping mill located in the historic Norfolk
Broads National Park, situated beside the River Ant, upstream from the
Sutton Broads. The house was a residence for the Keeper of the Mill
until 1900, when the advent of electricity rendered wind-powered pumps
obsolete. Since the end of its working life, the house has been used as a
private residence, but has remained an important piece of local
heritage, standing adjacent to the well-known historic grade 2 listed
Hunsett Mill.

Building History

Throughout its life in the
20th century, the house suffered from a series of ill-conceived
extensions, added to alleviate the original house’s spatial
shortcomings. All of these extensions negatively affected the setting of
the original house and caused subsidence and repeated flooding.

ground floor plan

second floor plan

When
the owners of the house needed further space, it was decided not to add
yet another incremental extension, but to re-instate the tiny 19th
century Mill Keeper’s house to its original proportions, with only a
single new extension added to one side.

The new extension

In
order for the new extension to retreat behind the listed setting of the
mill, the new addition is conceived as a shadow of the existing house.
By adding a dark volume to the existing brick volume and by virtue of
the chosen facade geometry, the exact shape of the extension volume
seems ambiguous from afar. When inspected at closer distance, the
radically modern approach is mediated by the image of pitched roofs and
dark timber boards that are a historic part of the Broads vernacular
language. The massing and proportions of the new addition are configured
to remain subordinate to the original building, yet the charred timber
cladding helps it to settle into its context. The intervention appears
as if it always belonged to the site, without reverting to false mimicry
of the vernacular. The extension is made entirely from solid laminated wood,
exposed as interior finish and clad in charred cedar boards externally.
Ground source heat pumps, passive solar heating and independent water
well supply make the house almost fully self-sufficient.

Design

The
house had been extended 5 times in the 20th century, with each
extension adding on specific new rooms like kitchen, bathroom and
bedroom, but the resulting agglomeration of extensions was aesthetical-
ly and functionally of very low quality. The client requested an
enlarge- ment of the house to create more open living spaces and two
additional bedrooms. Rather than adding on any more extensions, the
design team decided to demolish all previous extensions and to return
the cottage to its original shape, with only one new extension added in
the back. Planning restrictions allowed only very slight increase in
floorspace over the previous dwelling, and imposed tight restrictions on
roof heights, limiting any extensions to the ridge heights of the
existing cottage.

The
extension overcomes these limitations of size and height by creat- ing a
very open ground floor layout with three small, double height spaces
that create an impression of spatial generosity and allow for the
placement of large windows looking out towards the Mill and over the
marshes. The open ground floor is structured by a fireplace and changes
in floor level to create distinct kitchen, dining and living areas (3).
The first floor contains all of the 5 bedrooms as well as two bathrooms,
interspersed with the voids created by the double-height spaces. While
some of the bedrooms are only 7 square metres in size, they use the
space under the roof pitches, full height mirrors on some walls, large
external windows as well as internal windows into the void and towards
the ground floor living rooms to create a feeling of capaciousness.
All
internal walls and ceilings consist of the exposed timber structure.
The exposure of the structure captures the essence of the geometry and
materiality of the interior. The purity of the finish is assured by
careful detailing and concealment of servicing. Where doors were
required in timber walls, they were built to match the thickness and
finish to create a continuity of material feel and appearance. Space is
optimised by integrating fittings, wardrobes and the fireplace into the
timber walls. Limestone tiling for the bathrooms is colour matched to
the exposed timber so that there is little visual distinction between
them and the rest of the house.

The
main staircase is designed as light and unobtrusive as possible. It was
manufactured from 4mm steel plates which are sunk into a slotted recess
in the solid timber wall. The majority of floors are finished with
limed, dark baked oak planks to compliment the golden hue of the larch
timber walls. In order for the staircase threads to become continuous
with the floor, 3mm baked oak strips were directly bonded to the mild
steel and limed in place.
Much like the original cottage, openings
are arranged to first respond to the internal configuration. Every room
is flooded with natural daylight, and blessed with framed views of the
wind mill and surround- ing landscape. Glazing in the kitchen rests on
the worktops and permits views to the garden. Fixed panes of glass form a
continuous surface with the cladding, to integrate with the geometry of
the exterior and assure the air tightness of the interior, which relies
instead on regulated stack effect ventilation through openings in the
roof.